Insular and prelimbic cortices control behavioral accuracy and precision in a temporal decision-making task in rats

The anterior insular cortex (AIC) comprises a region of sensory integration. It appears to detect salient events in order to guide goal-directed behavior, code tracking errors, and estimate the passage of time. Temporal processing in the AIC may be instantiated by the integration of representations of interoception. Projections between the AIC and the medial prefrontal cortex (mPFC) - found both in rats and humans - also suggest a possible role for these structures in the integration of autonomic responses during ongoing behavior. Few studies, however, have investigated the role of AIC and mPFC in decision-making and time estimation tasks. Moreover, their findings are not consistent, so the relationship between temporal decision-making and those areas remains unclear. The present study employed bilateral inactivations to explore the role of AIC and prelimbic cortex (PL) in rats during a temporal decision-making task. In this task, two levers are available simultaneously (but only one is active), one predicting reinforcement after a short, and the other after a long-fixed interval. Optimal performance requires a switch from the short to the long lever after the short-fixed interval elapsed and no reinforcement was delivered. Switch behavior from the short to the long lever was dependent on AIC and PL. During AIC inactivation, switch latencies became more variable, while during PL inactivation switch latencies became both more variable and less accurate. These findings point to a dissociation between AIC and PL in temporal decision-making, suggesting that the AIC is important for temporal precision, and PL is important for both temporal accuracy and precision.

Early weight gain as a predictor of weight restoration in avoidant/restrictive food intake disorder

BACKGROUND

Previous research has demonstrated that early weight gain in family-based treatment (FBT) is predictive of remission for adolescents with anorexia nervosa (AN). However, no published data has addressed if early weight gain is also predictive of reaching weight restoration (i.e., 95% EBW) in patients with avoidant/restrictive food intake disorder (ARFID). Furthermore, no studies have evaluated the performance of the statistical models used to predict weight restoration at the end of treatment. This study sought to examine whether early weight gain in ARFID is predictive of weight restoration at 20 weeks using ROC analysis. Additionally, this study assessed how accurately the model classified patients and what types of misclassifications occurred.

METHODS

Participants (n = 130, 57.7% cisgender female 70.0% white) received virtual outpatient FBT. Receiver operating characteristics (ROC) were used to predict successful weight restoration at end of treatment, using early weight gain as the predictor. Twenty weeks was considered as the end of treatment, to align with the definition of end of treatment in FBT clinical trials. ROC analyses demonstrated that gaining at least 6.2 pounds by week 5 of treatment was the strongest predictor of achieving 95% EBW at 20 weeks (AUC = 0.72 [0.63, 0.81]). ROC analyses misclassified 35% of patients; the most common misclassification was predicting that a patient would not achieve 95% EBW when they actually did (61.6%). A logistical regression model, which included the patients' %EBW at admission in addition to early weight gain as a predictor, outperformed the ROC analyses (AUC = 0.90 [0.85, 0.95]) and provided additional context by showing the probability that a patient would succeed.

CONCLUSION

Taken together, research demonstrates that early weight gain is a useful predictor of 95% EBW at 20 weeks of treatment for patients with ARFID who require weight restoration. Furthermore, results suggest that statistical models need to take into account additional information, such as %EBW at admission, along with early weight gain in order to more accurately predict which patients will reach weight restoration at week 20.

Eating Disorder Clinical Presentation and Treatment Outcomes by Gender Identity Among Children, Adolescents, and Young Adults

PURPOSE

Current eating disorder treatment approaches for youth were developed for use with cisgender girls, which limits the understanding of effectiveness for cisgender boys and transgender and gender expansive (TGE) youth. Here, we compare treatment outcomes for cisgender boys and TGE youth with cisgender girls receiving family-based treatment for an eating disorder.

METHODS

Patients were aged 6-24 and either active in treatment or discharged from September 1, 2020, to November 1, 2022 (N = 1,235). Patient exposure to treatment varied given individualized length of treatment. Outcomes include eating disorder symptoms, depression, anxiety, suicidality, caregiver burden, and parental confidence in supervising treatment. Treatment outcomes for cisgender boys and TGE youth were compared with cisgender girls.

RESULTS

Patients included n = 975 cisgender girls, n = 152 cisgender boys, and n = 108 TGE youth. Anorexia nervosa was the most common diagnosis. Cisgender boys reported significantly lower eating disorder (b = -2.7 [-4.1, -1.3]), anxiety (b = -1.6 [-2.2, -0.9]), and depression (b = -1.7 [-2.4, -0.9]) symptoms at admission compared with cisgender girls. TGE patients had significantly higher anxiety (b = 1.08 [0.28, 1.91]) and depression (b = 1.72 [0.78, 2.65]) symptoms compared with cisgender girls. Cisgender boys started with significantly lower suicidal ideation (b = -1.28 [-2.19, -0.43]) and TGE patients with significantly higher suicidal ideation (b = 1.63 [0.76, 2.51]) than cisgender girls. All symptoms improved during treatment and improved at similar rates over time in treatment regardless of gender identity.

DISCUSSION

Early evidence from this study supports the use of family-based treatment for cisgender boys and TGE youth with eating disorders. Further research is needed on the long-term outcomes of this approach for youth of all genders.

CD4+ T cell immunity against cutaneous melanoma encompasses multifaceted MHC II-dependent responses

Whereas CD4+ T cells conventionally mediate antitumor immunity by providing help to CD8+ T cells, recent clinical studies have implied an important role for cytotoxic CD4+ T cells in cancer immunity. Using an orthotopic melanoma model, we provide a detailed account of antitumoral CD4+ T cell responses and their regulation by major histocompatibility complex class II (MHC II) in the skin. Intravital imaging revealed prominent interactions of CD4+ T cells with tumor debris-laden MHC II+ host antigen-presenting cells that accumulated around tumor cell nests, although direct recognition of MHC II+ melanoma cells alone could also promote CD4+ T cell control. CD4+ T cells stably suppressed or eradicated tumors even in the absence of other lymphocytes by using tumor necrosis factor-α and Fas ligand (FasL) but not perforin-mediated cytotoxicity. Interferon-γ was critical for protection, acting both directly on melanoma cells and via induction of nitric oxide synthase in myeloid cells. Our results illustrate multifaceted and context-specific aspects of MHC II-dependent CD4+ T cell immunity against cutaneous melanoma, emphasizing modulation of this axis as a potential avenue for immunotherapies.

The timing database: An open-access, live repository for interval timing studies

Interval timing refers to the ability to perceive and remember intervals in the seconds to minutes range. Our contemporary understanding of interval timing is derived from relatively small-scale, isolated studies that investigate a limited range of intervals with a small sample size, usually based on a single task. Consequently, the conclusions drawn from individual studies are not readily generalizable to other tasks, conditions, and task parameters. The current paper presents a live database that presents raw data from interval timing studies (currently composed of 68 datasets from eight different tasks incorporating various interval and temporal order judgments) with an online graphical user interface to easily select, compile, and download the data organized in a standard format. The Timing Database aims to promote and cultivate key and novel analyses of our timing ability by making published and future datasets accessible as open-source resources for the entire research community. In the current paper, we showcase the use of the database by testing various core ideas based on data compiled across studies (i.e., temporal accuracy, scalar property, location of the point of subjective equality, malleability of timing precision). The Timing Database will serve as the repository for interval timing studies through the submission of new datasets.

The assessment of caregiver self-efficacy in a virtual eating disorder setting

BACKGROUND

Caregiver self-efficacy is thought to be a key component for successful family-based treatment (FBT) for individuals with eating disorders. As such, interventions aimed at enhancing caregiver self-efficacy, often measured via the Parents Versus Anorexia scale, have been a focal point of FBT literature. However, studies looking at the relationship between caregiver self-efficacy and treatment outcomes have been mixed. We aimed to better understand the influence of caregiver self-efficacy on eating disorder treatment outcomes during FBT.

METHODS

Caregiver self-efficacy was measured using the Parents Versus Eating Disorders (PVED) scale, an adapted version of the Parents Versus Anorexia scale, in a sample of 1051 patients with an eating disorder and 1528 caregivers (patients can have more than one caregiver) receiving virtual FBT. Across two multilevel models, we tested how caregiver self-efficacy changed over time and its association with changes in eating disorder symptoms and weight over the first 16 weeks of treatment.

RESULTS

Over treatment, PVED scores increased (b = 0.79, SE = 0.04, CI [0.72, 0.86]) and starting PVED scores were predictive of improved eating disorder symptoms (b = - 0.73, SE = 0.22, CI [- 1.15, - 0.30]), but not weight (b = - 0.96, SE = 0.59, CI [- 2.10, 0.19]). We also found that PVED change-from-baseline scores were predictive of weight (b = - 0.48, SE = 0.03, CI [- 0.53, - 0.43]) such that patient weight was lower when caregiver reports of PVED were higher. Likewise, the association between caregiver change in PVED scores and weight varied as a function of treatment time (b = 0.27, SE = 0.01, CI [0.24, 0.29]). Results were consistent when isolating patients with anorexia nervosa.

CONCLUSIONS

Caregiver self-efficacy during FBT improved over time but was not robustly associated with treatment outcomes. This may, in part, be due to psychometric properties of the PVED scale. We describe these issues and illustrate the need for development of a new measure of self-efficacy for caregivers supporting their loved ones through eating disorder treatment.

Food insecurity among youth seeking eating disorder treatment

Food Insecurity (FI) is associated with a myriad of mental health concerns in children and adolescents. Eating disorder (ED) risk is higher in youth experiencing FI, and FI in childhood is associated with ED diagnoses later in life. Although a growing body of research has shown that FI is associated with a heightened risk for ED-related symptoms, little is known about how experiencing FI may impact ED treatment, particularly in youth. In this study, we characterize the treatment characteristics of youth aged 6-24 (N = 729) with FI receiving family-based treatment for an ED. FI was defined as self-reported experience of FI (family-level FI) at treatment admission, and living in a low income, low access area according to USDA census tract data. Seventeen patients (2.3 % of sample) self-reported family-level FI at intake and 24 (3.3 % of sample) were designated as living in a low income/low access location. Descriptive analyses only were used to characterize the sample due to sample sizes. Group means on measures of weight, ED symptomatology, depression, anxiety, and caregiver burden were evaluated at admission and after four, eight, 12, 16, and 20 weeks of treatment. Results characterize how FI may impact ED treatment and showcase variation in changes. ED treatment must be responsive to needs related to FI as access to and consumption of food is the very foundation of ED treatment.

Intratumoral CD8+ T cells with a tissue-resident memory phenotype mediate local immunity and immune checkpoint responses in breast cancer

CD8⁺ tumor-infiltrating lymphocytes with a tissue-resident memory T (T_RM) cell phenotype are associated with favorable prognosis in patients with triple-negative breast cancer (TNBC). However, the relative contribution of CD8⁺ T_RM cells to anti-tumor immunity and immune checkpoint blockade efficacy in breast cancer remains unknown. Here, we show that intratumoral CD8⁺ T cells in murine mammary tumors transcriptionally resemble those from TNBC patients. Phenotypic and transcriptional studies established two intratumoral sub-populations: one more enriched in markers of terminal exhaustion (T_EX-like) and the other with a bona fide resident phenotype (T_RM-like). Treatment with anti-PD-1 and anti-CTLA-4 therapy resulted in expansion of these intratumoral populations, with the T_RM-like subset displaying significantly enhanced cytotoxic capacity. T_RM-like CD8⁺ T cells could also provide local immune protection against tumor rechallenge and a T_RM gene signature extracted from tumor-free tissue was significantly associated with improved clinical outcomes in TNBC patients treated with checkpoint inhibitors.

Evaluating differences in setting expected body weight for children and adolescents in eating disorder treatment

OBJECTIVE

Weight restoration or weight gain is a common goal in eating disorder treatment. However, approaches to determine expected body weight (EBW) vary. A standardized approach based on normative data for a patient's age and gender uses weight associated with median BMI (mBMI). An individualized approach predicts EBW based on a patient's individual growth trajectory. Little research has examined differences in these approaches.

METHOD

Weight and clinical data were collected from patients ages 6-20 enrolled in virtual eating disorder treatment. EBW associated with mBMI was compared with EBW using the individualized approach. Linear mixed effects models examined differences in weight, eating disorder symptoms, depression, and anxiety, and whether EBW approach varied by patient characteristics.

RESULTS

Patients (N = 609) were on average age 15.6 (2.29), 85% were cisgender female, and predominantly diagnosed with anorexia nervosa (83.1%). The individualized approach led to significantly higher EBW on average (mean difference = 8.4 lbs [SE: .75]; p < .001) compared to mBMI; 70% of patients had a higher EBW using the individualized approach. Notably, EBW varied based on gender and diagnosis and it took longer on average to achieve individualized EBW. Time was the strongest predictor of changes in psychosocial outcomes and there were no significant differences by EBW approach.

DISCUSSION

Results from this study indicate that an individualized approach led to significantly higher EBWs compared with using mBMI. As underestimation of EBW may lead to higher risk of relapse, eating disorder professionals should consider using an individualized approach for setting EBW.

PUBLIC SIGNIFICANCE

For eating disorder patients who need to gain weight, accurately estimating target body weight for eating disorder treatment is critical to recovery and preventing relapse. An individualized, patient-centered approach to estimating target body weight more accurately estimated target body weight than the standardized, median body mass index approach. Using an individualized approach to treatment may improve a patient's likelihood of full recovery.

Effectiveness of delivering evidence-based eating disorder treatment via telemedicine for children, adolescents, and youth

Barriers limit access to eating disorder treatment. Evidence-based treatment delivered using telemedicine could expand access. This study determined the effectiveness of enhanced Family-Based Treatment (FBT+) delivered using telemedicine for children and adolescents with eating disorders. Participants had a confirmed eating disorder diagnosis, lived in states where treatment was available, and lived with a family member willing to participate. Virtual FBT+ was administered by a five-person team including a therapist, dietitian, medical provider, peer mentor, and family mentor for up to 12 months. Measures were recorded at baseline and varying frequencies throughout treatment. Weight was self-reported. Eating disorder symptoms were assessed with the Eating Disorder Examination-Questionnaire Short Form (EDE-QS) and depression and anxiety were measured using the Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7). Caregiver burden and self-efficacy were measured using the Burden Assessment Scale, and Parent Versus Eating Disorder scale. The majority of patients (N = 210; 6 to 24 years old [mean 16 · 1 years]) were cisgender female (83%) White, (71%), required weight restoration (78%), and had anorexia nervosa, restricting type (63%). After 16 weeks, patients on weight restoration gained on average 11 · 3 [9 · 86, 12 · 8] pounds and the average change in EDE-QS score was -6 · 31 [-8 · 67, -4 · 10] points. Similar reductions were seen for depression (-2 · 62 [-4 · 24, -1 · 04]), anxiety (-1 · 44 [-1 · 12, 0 · 78]), and caregiver burden (-4 · 41 [2 · 45, 6 · 31]). Caregiver self-efficacy increased by 4 · 56 [3 · 53, 5 · 61] points. Patients and caregivers reported satisfaction with treatment. Virtual FBT+ for eating disorders can transcend geographical and psychosocial treatment barriers, expanding access to evidence-based eating disorder treatment.

Problematic social media use is associated with the evaluation of both risk and ambiguity during decision making

BACKGROUND AND AIMS

People can engage in excessive, maladaptive use of social media platforms. This problematic social media use mirrors substance use disorders with regard to symptoms and certain behavioral situations. For example, individuals with substance use disorders demonstrate aberrations in risk evaluations during decision making, and initial research on problematic social media use has revealed similar findings. However, these results concerning problematic social media use have been clouded by tasks that involve learning and that lack a clear demarcation between risky and ambiguous decision making. Therefore, we set out to specifically determine the relationship between problematic social media use and decision making under both risk and ambiguity, in the absence of learning.

METHODS

We assessed each participant's (N = 90) self-reported level of problematic social media use. We then had them perform the wheel of fortune task, which has participants make choices between a sure option or either a risky or ambiguous gamble. In this way, the task isolates decisions made under risk and ambiguity, and avoids trial-to-trial learning. Results: We found that the greater an individual's problematic social media use, the more often that individual choses high-risk gambles or ambiguous gambles, regardless of the degree of ambiguity.

DISCUSSION AND CONCLUSIONS

Our findings indicate that greater problematic social media use is related to a greater affinity for high-risk situations and overall ambiguity. These findings have implications for the field, specifically clarifying and extending the extant literature, as well as providing future avenues for research.

Ptpn2 and KLRG1 regulate the generation and function of tissue-resident memory CD8+ T cells in skin

Tissue-resident memory T cells (T_RM cells) are key elements of tissue immunity. Here, we investigated the role of the regulator of T cell receptor and cytokine signaling, Ptpn2, in the formation and function of T_RM cells in skin. Ptpn2-deficient CD8⁺ T cells displayed a marked defect in generating CD69⁺ CD103⁺ T_RM cells in response to herpes simplex virus type 1 (HSV-1) skin infection. This was accompanied by a reduction in the proportion of KLRG1⁻ memory precursor cells and a transcriptional bias toward terminal differentiation. Of note, forced expression of KLRG1 was sufficient to impede T_RM cell formation. Normalizing memory precursor frequencies by transferring equal numbers of KLRG1⁻ cells restored T_RM generation, demonstrating that Ptpn2 impacted skin seeding with precursors rather than downstream T_RM cell differentiation. Importantly, Ptpn2-deficient T_RM cells augmented skin autoimmunity but also afforded superior protection from HSV-1 infection. Our results emphasize that KLRG1 repression is required for optimal T_RM cell formation in skin and reveal an important role of Ptpn2 in regulating T_RM cell functionality.

The Peak Interval Procedure in Rodents: A Tool for Studying the Neurobiological Basis of Interval Timing and Its Alterations in Models of Human Disease

Animals keep track of time intervals in the seconds to minutes range with, on average, high accuracy but substantial trial-to-trial variability. The ability to detect the statistical signatures of such timing behavior is an indispensable feature of a good and theoretically-tractable testing procedure. A widely used interval timing procedure is the peak interval (PI) procedure, where animals learn to anticipate rewards that become available after a fixed delay. After learning, they cluster their responses around that reward-availability time. The in-depth analysis of such timed anticipatory responses leads to the understanding of an internal timing mechanism, that is, the processing dynamics and systematic biases of the brain's clock. This protocol explains in detail how the PI procedure can be implemented in rodents, from training through testing to analysis. We showcase both trial-by-trial and trial-averaged analytical methods as a window into these internal processes. This protocol has the advantages of capturing timing behavior in its full-complexity in a fashion that allows for a theoretical treatment of the data.

Organ-specific isoform selection of fatty acid binding proteins in tissue-resident lymphocytes

Tissue-resident memory T (TRM) cells exist throughout the body where they are poised to mediate local immune responses. Although studies have defined a common mechanism of residency independent of location, there is likely to be a level of specialization that adapts TRM cells to their given tissue of lodgment. It has been shown that TRM cells in the skin rely on the uptake of exogenous fatty acids for their survival and upregulate fatty acid binding proteins (FABP) 4 and FABP 5 as part of their transcriptional program. However, FABPs exist as a larger family of isoforms with different members selected in a tissue-specific fashion that is optimized for local fatty acid availability. Here we show that although TRM cells in a range of tissue widely express FABPs, they are not restricted to FABP 4 and 5. Instead, TRM cells show varying patterns of isoform usage that are determined by tissue-derived factors. These patterns are malleable since TRM cells relocated to different organs modify their FABP expression in line with their new location. As a consequence, these results argue for tissue-specific overlays to the TRM cell residency program, including FABP expression that is tailored to the particular tissue of TRM cell lodgment.

Organ-specific isoform selection of fatty acid–binding proteins in tissue-resident lymphocytes

Tissue-resident memory T (TRM) cells exist throughout the body, where they are poised to mediate local immune responses. Although studies have defined a common mechanism of residency independent of location, there is likely to be a level of specialization that adapts TRM cells to their given tissue of lodgment. It has been shown that TRM cells in the skin rely on the uptake of exogenous fatty acids for their survival and up-regulate fatty acid–binding protein 4 (FABP4) and FABP5 as part of their transcriptional program. However, FABPs exist as a larger family of isoforms, with different members selected in a tissue-specific fashion that is optimized for local fatty acid availability. Here, we show that although TRM cells in a range of tissue widely express FABPs, they are not restricted to FABP4 and FABP5. Instead, TRM cells show varying patterns of isoform usage that are determined by tissue-derived factors. These patterns are malleable because TRM cells relocated to different organs modify their FABP expression in line with their new location. As a consequence, these results argue for tissue-specific overlays to the TRM cell residency program, including FABP expression that is tailored to the particular tissue of TRM cell lodgment.

The importance of migratory connectivity for global ocean policy

The distributions of migratory species in the ocean span local, national and international jurisdictions. Across these ecologically interconnected regions, migratory marine species interact with anthropogenic stressors throughout their lives. Migratory connectivity, the geographical linking of individuals and populations throughout their migratory cycles, influences how spatial and temporal dynamics of stressors affect migratory animals and scale up to influence population abundance, distribution and species persistence. Population declines of many migratory marine species have led to calls for connectivity knowledge, especially insights from animal tracking studies, to be more systematically and synthetically incorporated into decision-making. Inclusion of migratory connectivity in the design of conservation and management measures is critical to ensure they are appropriate for the level of risk associated with various degrees of connectivity. Three mechanisms exist to incorporate migratory connectivity into international marine policy which guides conservation implementation: site-selection criteria, network design criteria and policy recommendations. Here, we review the concept of migratory connectivity and its use in international policy, and describe the Migratory Connectivity in the Ocean system, a migratory connectivity evidence-base for the ocean. We propose that without such collaboration focused on migratory connectivity, efforts to effectively conserve these critical species across jurisdictions will have limited effect.

Theoretical implications of quantitative properties of interval timing and probability estimation in mouse and rat

In three experiments with mice ( Mus musculus ) and rats (Rattus norvigicus), we used a switch paradigm to measure quantitative properties of the interval-timing mechanism. We found that: 1) Rodents adjusted the precision of their timed switches in response to changes in the interval between the short and long feed latencies (the temporal goalposts). 2) The variability in the timing of the switch response was reduced or unchanged in the face of large trial-to-trial random variability in the short and long feed latencies. 3) The adjustment in the distribution of switch latencies in response to changes in the relative frequency of short and long trials was sensitive to the asymmetry in the Kullback-Leibler divergence. The three results suggest that durations are represented with adjustable precision, that they are timed by multiple timers, and that there is a trial-by-trial (episodic) record of feed latencies in memory.

Distinct mechanisms govern resident memory T cell differentiation and survival in different tissues

Tissue-resident memory T (Trm) cells are a recently defined population of memory T cells that persist at the site of previous infection and contribute to protective local immunity. Trm cells have been identified in both epithelial and solid organs; however, despite their ubiquity, they share molecular commonalities that are distinct from circulating memory T cells. Therefore, we sought to explore the transcriptional regulation of Trm cells in a number of different organs. Our earlier data demonstrated that Trm cells share a core transcriptional signature regulated by the two related transcription factors Hobit and Blimp1. Here we show that Trm cells also have distinct molecular requirements according to anatomic location. While Hobit was uniquely required for the development of Trm cells in all organs tested, Blimp1 was required in some organs, but dispensable in others. Similar to Blimp1, the T-box transcription factor T-bet was also required for Trm cell development in only a subset of organs. This differential transcription factor dependency was linked to distinct cytokine requirements for Trm cell development in different organs. Trm cell defects were enhanced in the absence of multiple transcription factors, suggesting functional redundancy and implicating a role for distinct transcriptional networks as drivers of Trm cell development in different organs. Together, these data demonstrate the adaptation of Trm cells to specific tissue microenvironments and highlight the importance of studying these cells in a variety of organs.

Ceruloplasmin is regulated by copper and lactational hormones in PMC42-LA mammary epithelial cell culture models

Ceruloplasmin (Cp) is a multicopper ferroxidase that is considered to be an important source of copper in milk for normal neonatal development. We investigated the expression, subcellular localization and secretion of Cp in PMC42-LA cell culture models representative of resting, lactating and suckled human mammary epithelia. Both secreted Cp (sCp) and plasma membrane associated glycosylphosphatidylinositol-linked Cp (GPI-Cp) were expressed in PMC42-LA cells. In all three epithelial models (resting, lactating and suckled), the expression and secretion of copper-bound, ferroxidase active, Cp (holo-Cp) was dependent on media copper concentration. In low copper (bathocuproinedisulphonic acid/d-penicillamine treated models) there was greater than a 2-fold decrease in holo-Cp expression and secretion, which was mirrored by a 2-fold increase in the expression and secretion of copper-free Cp protein (apo-Cp). Cell surface biotinylation studies revealed that the state of PMC42-LA cell differentiation (functionality), and the level of extracellular copper, had no significant effect on the level of plasma membrane bound GPI-Cp. Quantitative real time PCR analyses determined that there was no significant (P > 0.05) difference in Cp mRNA levels across all copper conditions investigated (0, 5, 50 μM). However, there was a significant (P < 0.05) increase (∼2-fold) in Cp mRNA in both the lactating and suckled models in comparison to the resting model. Furthermore, the Cp mRNA increase in response to PMC42-LA differentiation corresponded with more secreted Cp protein, both apo and holo forms, indicating a link between function and Cp requirement. Our results provide significant insight on the regulation of Cp expression and secretion in lactation and copper incorporation into milk.

Amyloid-beta accumulation, neurogenesis, behavior, and the age of rats

The goals of this research were to describe age-related changes in brain biochemistry and behavior, and the relationships between them. The chronological ages of greatest change are particularly important for targeting interventions. In this experiment, 36 Fischer 344/Brown-Norway rats (3, 12, 20, and 30 months old) were trained in lever boxes on temporal discrimination tasks. The greatest response rate decrease and response pattern change occurred between 12 and 20 months. The biochemical results showed that amyloid-beta peptides (Aβ40 and Aβ42) increased with age. The endothelial expression of the Aβ influx transporter (RAGE) also increased, and the expression of Aβ efflux transporter (LPR-1) decreased, with age. The greatest change in the biochemical measures also were between 12 and 20 months. Twenty additional rats were analyzed for stem cell proliferation, and neurogenesis decreased with age, particularly between about 12 and 20 months. These early changes in brain, biochemistry, and behavior provide opportunity for new therapies or prophylaxis.

Automated, quantitative cognitive/behavioral screening of mice: for genetics, pharmacology, animal cognition and undergraduate instruction

We describe a high-throughput, high-volume, fully automated, live-in 24/7 behavioral testing system for assessing the effects of genetic and pharmacological manipulations on basic mechanisms of cognition and learning in mice. A standard polypropylene mouse housing tub is connected through an acrylic tube to a standard commercial mouse test box. The test box has 3 hoppers, 2 of which are connected to pellet feeders. All are internally illuminable with an LED and monitored for head entries by infrared (IR) beams. Mice live in the environment, which eliminates handling during screening. They obtain their food during two or more daily feeding periods by performing in operant (instrumental) and Pavlovian (classical) protocols, for which we have written protocol-control software and quasi-real-time data analysis and graphing software. The data analysis and graphing routines are written in a MATLAB-based language created to simplify greatly the analysis of large time-stamped behavioral and physiological event records and to preserve a full data trail from raw data through all intermediate analyses to the published graphs and statistics within a single data structure. The data-analysis code harvests the data several times a day and subjects it to statistical and graphical analyses, which are automatically stored in the "cloud" and on in-lab computers. Thus, the progress of individual mice is visualized and quantified daily. The data-analysis code talks to the protocol-control code, permitting the automated advance from protocol to protocol of individual subjects. The behavioral protocols implemented are matching, autoshaping, timed hopper-switching, risk assessment in timed hopper-switching, impulsivity measurement, and the circadian anticipation of food availability. Open-source protocol-control and data-analysis code makes the addition of new protocols simple. Eight test environments fit in a 48 in x 24 in x 78 in cabinet; two such cabinets (16 environments) may be controlled by one computer.

Copper and lactational hormones influence the CTR1 copper transporter in PMC42-LA mammary epithelial cell culture models

Adequate amounts of copper in milk are critical for normal neonatal development, however the mechanisms regulating copper supply to milk have not been clearly defined. PMC42-LA cell cultures representative of resting, lactating and suckled mammary epithelia were used to investigate the regulation of the copper uptake protein, CTR1. Both the degree of mammary epithelial differentiation (functionality) and extracellular copper concentration greatly impacted upon CTR1 expression and its plasma membrane association. In all three models (resting, lactating and suckling) there was an inverse correlation between extracellular copper concentration and the level of CTR1. Cell surface biotinylation studies demonstrated that as extracellular copper concentration increased membrane associated CTR1 was reduced. There was a significant increase in CTR1 expression (total and membrane associated) in the suckled gland model in comparison to the resting gland model, across all copper concentrations investigated (0-50 μM). Regulation of CTR1 expression was entirely post-translational, as quantitative real-time PCR analyses showed no change to CTR1 mRNA between all models and culture conditions. X-ray fluorescence microscopy on the differentiated PMC42-LA models revealed that organoid structures distinctively accumulated copper. Furthermore, as PMC42-LA cell cultures became progressively more specialised, successively more copper accumulated in organoids (resting<lactating<suckling), indicating a link between function and copper requirement. Based on previous data showing a function for CTR1 in copper uptake, we have concluded that under the influence of hormones and increased extracellular copper levels, CTR1 participates in uptake of copper by mammary epithelial cells, as a prerequisite for secretion of copper into milk.

Optimal temporal risk assessment

Time is an essential feature of most decisions, because the reward earned from decisions frequently depends on the temporal statistics of the environment (e.g., on whether decisions must be made under deadlines). Accordingly, evolution appears to have favored a mechanism that predicts intervals in the seconds to minutes range with high accuracy on average, but significant variability from trial to trial. Importantly, the subjective sense of time that results is sufficiently imprecise that maximizing rewards in decision-making can require substantial behavioral adjustments (e.g., accumulating less evidence for a decision in order to beat a deadline). Reward maximization in many daily decisions therefore requires optimal temporal risk assessment. Here, we review the temporal decision-making literature, conduct secondary analyses of relevant published datasets, and analyze the results of a new experiment. The paper is organized in three parts. In the first part, we review literature and analyze existing data suggesting that animals take account of their inherent behavioral variability (their “endogenous timing uncertainty”) in temporal decision-making. In the second part, we review literature that quantitatively demonstrates nearly optimal temporal risk assessment with sub-second and supra-second intervals using perceptual tasks (with humans and mice) and motor timing tasks (with humans). We supplement this section with original research that tested human and rat performance on a task that requires finding the optimal balance between two time-dependent quantities for reward maximization. This optimal balance in turn depends on the level of timing uncertainty. Corroborating the reviewed literature, humans and rats exhibited nearly optimal temporal risk assessment in this task. In the third section, we discuss the role of timing uncertainty in reward maximization in two-choice perceptual decision-making tasks and review literature that implicates timing uncertainty as an important factor in performance quality. Together, these studies strongly support the hypothesis that animals take normative account of their endogenous timing uncertainty. By incorporating the psychophysics of interval timing into the study of reward maximization, our approach bridges empirical and theoretical gaps between the interval timing and decision-making literatures.

Antibiotics pollution in Jiulong River estuary: source, distribution and bacterial resistance

To gain insight into the antibiotic pollution in the Jiulong River estuary and the pollutant sources, we analyzed the concentration of 22 widely-used antibiotics in water samples collected from the river and estuary, 17 and 18 sampling sites, respectively. Contamination with sulfonamides, quinolones and chloramphenicols was frequently detected and the distribution pattern of antibiotics suggested that most of the pollutants are from the Jiulong River, especially from the downstream watersheds. To reveal the ecological effects, we isolated 35 bacterial strains from the estuary and analyzed their antibiotic resistance to the eight most frequently detected antibiotics. The bacteria were subsequently classified into seven different genera by 16SrDNA sequencing. Up to 97.1% of the bacteria showed resistance and 70.6% of strains showed multi-resistance to these antibiotics, especially to sulfonamides. This study demonstrated a pattern of antibiotic contamination in the Jiulong River and its estuary and illustrated high bacterial antibiotic resistance which was significantly correlated with the average antibiotics concentrations and detected frequencies in the estuary.

Reproductive toxic effects of sublethal cadmium on the marine polychaete Perinereis nuntia

To gain insight into the reproductive toxicity of sublethal cadmium on marine polychaetes, Perinereis nuntia sandworms were exposed to cadmium via artificially contaminated seawater. Cadmium influence on sexual maturation, egg laying, fertilization, zygote hatching and vitellogenin expression levels were analyzed. Results indicated that 23.05 and 563.87 microg L(-1) cadmium significantly delayed sexual maturation. Fertilization rate was significantly inhibited by 563.87 microg L(-1) cadmium while lower concentrations showed no significant effect. Zygote hatching was significantly inhibited by cadmium concentrations greater than 1.12 microg L(-1). We identified a vitellogenin gene sequence in P. nuntia and found that mRNA transcription was significantly upregulated by cadmium. These results indicate that sublethal cadmium levels cause dose-dependent reproductive toxicity on P. nuntia by inhibiting sexual maturation, fertilization and zygote hatching, and the increased expression of vitellogenin suggesting cadmium has strong feminization effects on polychaetes.

Screening for Learning and Memory Mutations: A New Approach

We describe a fully automated, live-in 24/7 test environment, with experimental protocols that measure the accuracy and precision with which mice match the ratio of their expected visit durations to the ratio of the incomes obtained from two hoppers, the progress of instrumental and classical conditioning (trials-to-acquisition), the accuracy and precision of interval timing, the effect of relative probability on the choice of a timed departure target, and the accuracy and precision of memory for the times of day at which food is available. The system is compact; it obviates the handling of the mice during testing; it requires negligible amounts of experimenter/technician time; and it delivers clear and extensive results from 3 protocols within a total of 7-9 days after the mice are placed in the test environment. Only a single 24-hour period is required for the completion of first protocol (the matching protocol), which is strong test of temporal and spatial estimation and memory mechanisms. Thus, the system permits the extensive screening of many mice in a short period of time and in limited space. The software is publicly available.

Risk assessment in man and mouse

Human and mouse subjects tried to anticipate at which of 2 locations a reward would appear. On a randomly scheduled fraction of the trials, it appeared with a short latency at one location; on the complementary fraction, it appeared after a longer latency at the other location. Subjects of both species accurately assessed the exogenous uncertainty (the probability of a short versus a long trial) and the endogenous uncertainty (from the scalar variability in their estimates of an elapsed duration) to compute the optimal target latency for a switch from the short- to the long-latency location. The optimal latency was arrived at so rapidly that there was no reliably discernible improvement over trials. Under these nonverbal conditions, humans and mice accurately assess risks and behave nearly optimally. That this capacity is well-developed in the mouse opens up the possibility of a genetic approach to the neurobiological mechanisms underlying risk assessment.

ATP7B expression in human breast epithelial cells is mediated by lactational hormones

A role for the copper transporter, ATP7B, in secretion of copper from the human breast into milk has previously not been reported, although it is known that the murine ortholog of ATP7B facilitates copper secretion in the mouse mammary gland. We show here that ATP7B is expressed in luminal epithelial cells in both the resting and lactating human breast, where it has a perinuclear localization in resting epithelial cells and a diffuse location in lactating tissue. ATP7B protein was present in a different subset of vesicles from those containing milk proteins and did not overlap with Menkes ATPase, ATP-7A, except in the perinuclear region of cells. In the cultured human mammary line, PMC42-LA, treatment with lactational hormones induced a redistribution of ATP7B from a perinuclear region to a region adjacent, but not coincident with, the apical plasma membrane. Trafficking of ATP7B was copper dependent, suggesting that the hormone-induced redistribution of ATP7A was mediated through an increase in intracellular copper. Radioactive copper ((64)Cu) studies using polarized PMC42-LA cells that overexpressed mAtp7B protein showed that this transporter facilitates copper efflux from the apical surface of the cells. In summary, our results are consistent with an important function of ATP7B in the secretion of copper from the human mammary gland.

Diesel exhaust particulate matter induces multinucleate cells and zinc transporter-dependent apoptosis in human airway cells

The cellular effects of biodiesel emissions particulate matter (BDEP) and petroleum diesel emissions particulate matter (PDEP) were compared using a human airway cell line, A549. At concentrations of 25 microg/ml, diesel particulate matter induced the formation of multinucleate cells. In cells treated with a mixture of 80% PDEP:20% BDEP, 52% of cells were multinucleate cells compared with only 16% of cells treated with 20% PDEP:80% BDEP with a background multinucleate rate of 7%. These results demonstrate a causal relation between the formation of multinucleate cells and exposure to exhaust particulate matter, in particular diesel exhaust. Exposure of A549 cells to PDEP induced apoptosis, seen by active caspase-3 expression and the presence of cleaved pancytokeratin. PDEP exhaust was a much stronger inducer of cellular death through apoptosis than BDEP. There was an eightfold increase in the expression of SLC30A3 (zinc transporter-3 or ZnT3) in cells exposed to 80% PDEP:20% BDEP compared to untreated cells. The increase in ZnT3 expression seen in apoptotic cells following PDEP suggests a role for this zinc transporter in the apoptotic pathway, possibly through controlling zinc fluxes. As exposure to diesel exhaust particles is associated with asthma and apoptosis in airway cells, diesel exhaust particles may directly contribute to asthma by inducing epithelial cell death through apoptotic pathway.